The present invention relates to an apparatus for transferring yarn package tubes on a textile machine, and more particularly, to an apparatus for transferring empty tubes and full yarn packages built on tubes between a support means and a plurality of spindles of a textile machine.
In a typical arrangement, a textile spinning or doubling machine includes a plurality of spindles uniformly spaced along the longitudinal extent of the textile machine on at least one side thereof. The spindles individually support tubes during the building of yarn thereon in a yarn package building operation during which full yarn packages are built on the tubes. In one conventional arrangement for supplying empty tubes to the spindles and for transporting full yarn packages from the spindles, an endless belt assembly is provided which includes an endless belt extending parallel to the row of spindles at a spacing therebelow. The endless belt is provided with two series of vertical posts, each post for individually supporting a tube inserted thereon, with the spacing between the vertical posts of each series being at the same uniform spacing as the spacing between the spindles.
The endless belt transports a plurality of empty tubes in upright dispositions to a transfer location below the row of spindles in preparation for transferring full yarn packages from the spindles to the vertical posts of one series of vertical posts and for transferring the empty tubes supported on the other series of vertical posts on the endless belt to the spindles. German patent DE 12 92 563 discloses one known device, commonly referred to as an auto-doffer, for effecting transfer of the empty tubes and full yarn packages between the endless belt and the spindles of a textile machine. The auto-doffer is vertically movable to raise and lower the respective pluralities of empty tubes or full yarn packages supported thereby and, additionally, the auto-doffer is laterally movable in a direction transverse to the row of spindles so that the supported tubes or packages can be moved laterally outwardly of the endless belt to clear the endless belt during the raising and lowering movements.
It is known to provide a plurality of mechanical switches, all connected to a control unit, for signaling the control unit that the auto-doffer has completed respective vertical and lateral movements so that the control unit can control the auto-doffer to commence subsequent vertical and lateral movements. These mechanical switches are adjustable to adjust the positioning of the auto doffer to properly position their gripping devices in relation to the particular tube and package position. The mechanical switches must typically be adjusted to new travel limits in preparation for operating the textile machine to build batches of yarn packages having different characteristics than a prior batch or batches of yarn packages built by the textile machine. Experience has shown that the alignment and adjustment of the mechanical switches requires a relatively high degree of labor and considerable time. Since the textile machine must necessarily be in a standstill condition during any re-adjustment of the mechanical switches, the production efficiency of the textile machine suffers as a result of the re-adjustment of the mechanical switches. Accordingly, the need still exists for an auto-doffer-type device for transferring empty tubes and full yarn packages between the spindles of a textile machines and a transport or support assembly which minimizes the time needed to adjust the auto-doffer to new movement routines.